Bringing electronic and mechanical designs to DIYer's and enthusiasts.


As a young boy in the 1960's I waited at my mail box at the beginning of each month eagerly anticipating all the new electronic and DIY project magazines. In the mid 90's I started writing for several of them bringing my own articles to DIYers everywhere and now that I'm retired that tradition continues. I hope you enjoy the projects I'm now bringing forward in AudioXpress and other publications.

contact Us: robert AT dsgnspec.0catch DOT com (no spaces)

About Us


For personal use only.
May not be copied,replicated, etc. without the written consent
of Robert Nance Dee.
For commercial use please contact us.

Latest Designs:


The Original Willow

It's named after the cat in the background.

Below is an updated digital pot that was in the October aX. It has 128 position. The button is a balance control. All this with only 12 precision resistors per channel. Each input (there are 4) lights a different color LED which can be seen on the perimeter of the case top. I built this as an interface for testing amps.(PI= Peripheral Interface)

PI is covered in the April 2012 issue of aX.

Merlyn is a tube headphone amp. This is the first version, an updated version appeared in the May 2012 issue of AudioXpress that expanded to be a headamp/preamp combo.

The original Merlyn:

The New Merlyn